\[\alpha \gt -1 \land \beta \gt -1\]
\[\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1}\]
\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1}
double f(double alpha, double beta) {
        double r145307 = alpha;
        double r145308 = beta;
        double r145309 = r145307 + r145308;
        double r145310 = r145308 * r145307;
        double r145311 = r145309 + r145310;
        double r145312 = 1.0;
        double r145313 = r145311 + r145312;
        double r145314 = 2.0;
        double r145315 = r145314 * r145312;
        double r145316 = r145309 + r145315;
        double r145317 = r145313 / r145316;
        double r145318 = r145317 / r145316;
        double r145319 = r145316 + r145312;
        double r145320 = r145318 / r145319;
        return r145320;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 +o rules:numerics
(FPCore (alpha beta)
  :name "Octave 3.8, jcobi/3"
  :precision binary64
  :pre (and (> alpha -1) (> beta -1))
  (/ (/ (/ (+ (+ (+ alpha beta) (* beta alpha)) 1) (+ (+ alpha beta) (* 2 1))) (+ (+ alpha beta) (* 2 1))) (+ (+ (+ alpha beta) (* 2 1)) 1)))

Backtrace

dict-ref: no value for key: 'branch145306 in: '((alpha . binary64) (beta . binary64))LC
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt1064
make-sampler/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt990
prepare-points-intervals/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt1210
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt2339
sindices->spoints/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt1940
f33/opt/racket-7.2/collects/racket/match/compiler.rkt50740
get-final-combination/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt3690
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.2/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.2/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128